New explanation for truck driver fatigue

Reporter: Mary Gearin

MAXINE McKEW: Well, with the Christmas holidays almost upon us, it's a time for enjoyment and for staying alert, particularly on those long drives to holiday destinations.

Fatigue is a problem that all drivers need to be conscious of, but it's potentially fatal for truck drivers, despite regulations intended to prevent them from being pushed beyond the limit of concentration.

Now, in what's being touted as a world first, Melbourne researchers say they've established that the vibrations experienced on long trips could be like rocking drivers to sleep, just like babies.

Mary Gearin reports.

MARY GEARIN: It's simply too hard to tell how much fatigue plays a part in fatalities and injuries on Australian roads.

Some studies say tiredness has been a factor in up to 40 per cent of all deaths involving trucks.

If you count lapses in concentration, the estimates soar.

Lawrie Melville now drives a truck for Melbourne's Swinburne University, but a year ago, he quit his job as a truckie for employers he calls 'unscrupulous' who, he says, pushed him to drive for up to 36 hours without sleep.

You took drugs?

LAWRIE MELVILLE, TRUCK DRIVER: Yeah, yeah.

Had to.

On some occasions it was a necessity.

It was either take something to stay awake or die.

MARY GEARIN: Rob Hill counts himself lucky, working for what he calls one of the few good guys in the industry, with generous rosters and speed limiters in the trucks, but he still sees plenty of cowboys on the road.

ROB HILL, TRUCK DRIVER: Every night on the road, guys who shouldn't be out there, they're tired and you will hear other truck drivers warn them over the radios now, "Get off the road.

Have a sleep."

MARY GEARIN: Entrenched exploitative industry cultures could take decades to overcome, but Melbourne researchers have begun to study one factor in driver fatigue they hope they can change.

Swinburne University last year began what's thought to be the first study to measure the cognitive effects of low-level vibrations on a driver, not the jarring bumps, but more gentle monotonous undulations, at 4 hertz, to be precise.

DR JOHN PATTERSON, SWINBURNE UNIVERSITY OF TECHNOLOGY: We have anecdotal evidence that if you are vibrated in certain ways, you tend to relax.

We have rocking chairs - we rock babies to sleep.

So, on a boat or bus or train you tend to relax.

We don't know whether that's a coincidence or whether it's almost predetermined by the vibration that you're exposed to.

ASSOCIATE PROFESSOR KERRY McMANUS, SWINBURNE UNIVERSITY OF TECHNOLOGY: There is anecdotal information of a truck driver - I think it was in Arizona or one of the American Midwest states - who was measured over eight hours of performance.

Over eight hours, he was literally asleep for 20 minutes, not for 20 minutes in one time, but for short bursts of sleep and we think that's an indication of this type of reactions occurring in the brain.

It's switching the brain off.

MARY GEARIN: 42 students and staff members were asked to perform a cognitive test before, during and after sitting through vibrations in a truckie's chair for 10 minutes.

GABRIELLE COLLANDER, EXPERIMENT SUBJECT: Definitely tired out like the back of my legs and my lower back, that sort of thing.

Sort of just really getting a bit drowsy sitting there for a fair while, especially while concentrating as well.

MARY GEARIN: A year on and John Patterson says he has interesting results.

Firstly, the experiment seems to confirm his basic proposition.

DR JOHN PATTERSON: Change in moods or emotions was always in the direction of latitude, fatigue, tiredness, sort of boredom, being turned off.

MARY GEARIN: More worrying was the change in reaction time for subjects who made a mistake while in the vibrating chair.

DR JOHN PATTERSON: It's a fair extrapolation, but what it would mean is if a person was driving the truck, for example, and if the seat was bouncing in the same frequency that we looked at, the person, if they were indecisive about an issue, maybe distracted momentarily, instead of reacting fairly quickly, their reactions will slow down significantly, such that the truck may travel an extra 3m, 4m along the road in that period of being distracted.

MARY GEARIN: The researchers were also able to locate exactly which parts of the brain were affected by changes in the frequency and they detected a change in the heart rate that would normally suggest stress, even though the subjects didn't report feeling stressed.

The study raises a challenge for engineers.

Modern truck seats have become sophisticated buffers against more dramatic shocks from the road.

ROB HILL: A lot of the seats now are air-suspended and they are very comfortable.

It's like sitting in an arm chair basically without the arms.

MARY GEARIN: But more attention could be needed to combat the subtle pulse of the road and its stealthy injuries.

DR JOHN PATTERSON: I don't think they've appreciated the impact of these sorts of vibrations at the lower end.

They've been more concerned about obvious driver comfort rather than the sort of subtle effects of driver attention and so forth.

MARY GEARIN: The Swinburne researchers hope their eventual recommendations regarding seat design could help keep drivers awake, but Rob Hill believes it's also essential to recalibrate the prevailing industry culture that urges drivers to push through the sleep barrier.

ROB HILL: The older blokes, not so much.

The young ones, yes.

As you see the younger ones coming through, you hear more and more, "I can do this, I did that," and that is a worry.